Antibiotic resistance is now seen as one of the major challenges facing modern medicine. Given the shortage of novel antibiotics, a number of alternative approaches are being investigated, including the use of bacteriophages as therapeutic agents (Harper, Anderson & Enright, Therapeutic Delivery (2011), 2, 935-947; Hausler T, Viruses vs. Superbugs: A Solution to the Antibiotics Crisis? (2006) MacMillan, New York.
Bacteriophages (often known simply as “phages”) are viruses that grow within bacteria. The name translates as “eaters of bacteria” and reflects the fact that as they grow most bacteriophages kill the bacterial host as the next generation of bacteriophages is released. Early work with bacteriophages was hindered by many factors, one of which was the widespread belief that there was only one type of bacteriophage, a non-specific virus that killed all bacteria. In contrast, it is now understood that the host range of bacteriophages (the spectrum of bacteria they are capable of infecting) is often very specific. This specificity, however, has the disadvantage that it is difficult to achieve breadth of adequate bacteriophage efficacy across bacterial target species/strains. There is therefore a need in the art for methods of identifying improved combinations of bacteriophages having effective targeting capability in relation to bacterial species/strains—see, for example, Pirsi, The Lancet (2000) 355, 1418. For these reasons, examples of phage compositions demonstrating sound clinical efficacy are very limited. By way of example, reference is made to Applicant's successful clinical trials (veterinary and human) conducted with a panel of bacteriophages that target Pseudomonas aeruginosa—see Wright et al, Clinical Otolaryngology (2009) 34, 349-357. There is therefore a need in the art to develop further panels of bacteriophages that have optimal clinical applicability.
In particular, there is a need in the art to design panels of two or more bacteriophages that target the same bacterial host species/strain, wherein said panel of bacteriophage provide adequate efficacy against a bacterial target species/strain when compared to the individual efficacy of said bacteriophage against said bacterial target species/strain. In this regard, it is necessary that the bacteriophage members of the panel work well together in a combination (e.g. the panel demonstrates equivalent or improved efficacy vis-à-vis the individual members thereof).
The present invention addresses one or more of the above problems.